#Millions begin the big Christmas and New Year getaway early
#Experts warn backlog of up to 4m parcels could remain undelivered
#NHS issues urgent appeal for blood donors after concerns of shortages
#Councils reveal plans to share grit amid fears of cold snap until January 14
#Odds shortened even further on ‘White Christmas’ in some parts of country

The Big Freeze will hold us in its grip for at least another month, forecasters warn.

Arctic conditions are expected to last through the Christmas and New Year bank holidays and beyond.

With temperatures expected to fall to -15c (5f), the Met Office said this is ‘almost certain’ to become the coldest December since records began in 1910.

Arctic conditions forced the cancellation of hundreds of flights from terminals up and down the country on what is traditionally the busiest weekend of the year for the travelling public.

Runway closures at Heathrow and Gatwick led to delays of several hours for those who did manage to fly, but with more heavy snow forecast for today, travellers have been warned that many more flights could be axed.

A total of 630,000 people were due to fly in and out of Heathrow this weekend, with another 240,000 due to pass through Gatwick and tens of thousands more at regional airports.

Sub-zero temperatures could last until the New Year, forecasters warned, casting doubt on the plans of four million Britons who had been planning to leave the country for holidays abroad.

The big freeze also brought roads and railway lines to a standstill in many parts of the country ahead of a weekend when 18 million motorists normally take to the roads.

Almost 1,000 businesses could go bust if the final weekend of Christmas shopping is badly disrupted by snow and ice.

Experts have warned that Britain could be shivering in temperatures colder than Siberia over the next few days.

Customers relying on home deliveries face an anxious wait, with hauliers warning that thousands of items could still be stuck in warehouses on Christmas morning.

Temperatures are expected to drop to -15C (5F) in the coming days, leaving Britain colder than the North Pole, the Arctic and Alaska.

It is feared that shops which have already been severely hit by freezing conditions in January and November will not be able to cope with a third spell of bad weather. Yesterday Amazon became the latest retailer to bring forward its final order deadline for guaranteed Christmas delivery while the shopping channels QVC and Ideal World said they could not guarantee that orders placed now would arrive in time for Christmas.

Douglas McWilliams, the chief executive of the Centre for Economics and Business Research, said: "As many as 800 or 900 businesses could go bankrupt which otherwise wouldn't have, because this is the straw that breaks the camel's back."